We report on the results of a time-series photometric survey of M50 (NGC 2323), a ~130Myr open cluster, carried out using the Cerro Tololo Inter-American Observatory (CTIO) 4-m Blanco telescope and Mosaic-II detector as part of the Monitor project. Rotation periods were derived for 812 candidate cluster members over the mass range 0.2<=M/M_{sun}_<=1.1. The rotation period distributions show a clear mass-dependent morphology, statistically indistinguishable from those in NGC 2516 and M35 taken from the literature. Due to the availability of data from three observing runs separated by ~10 and 1 month time-scales, we are able to demonstrate clear evidence for evolution of the photometric amplitudes, and hence spot patterns, over the 10 month gap. We are not able to constrain the time-scales for these effects in detail due to limitations imposed by the large gaps in our sampling, which also prevent the use of the phase information.
We report on the results of an i-band time-series photometric survey of NGC2516 using the Cerro Tololo Inter-American Observatory (CTIO) 4-m Blanco telescope and 8k Mosaic-II detector, achieving better than 1 per cent photometric precision per data point over 15<~i<~19. Candidate cluster members were selected from a V versus V-I colour-magnitude diagram over 16<V<26 (covering masses from 0.7M_{sun}_ down to below the brown dwarf limit), finding 1685 candidates, of which we expect ~1000 to be real cluster members, taking into account contamination from the field (which is most severe at the extremes of our mass range). Searching for periodic variations in these gave 362 detections over the mass range 0.15<~M/M_{sun}_<~0.7. The rotation period distributions were found to show a remarkable morphology as a function of mass, with the fastest rotators bounded by P>0.25d, and the slowest rotators for M<~0.5M_{sun}_ bounded by a line of P~M3, with those for M>~0.5M_{sun}_ following a flatter relation closer to P ~ constant. Models of the rotational evolution were investigated, finding that the evolution of the fastest rotators was well reproduced by a conventional solid body model with a mass-dependent saturation velocity, whereas core-envelope decoupling was needed to reproduce the evolution of the slowest rotators. None of our models were able to simultaneously reproduce the behaviour of both populations.
We report on the results of an I-band time-series photometric survey of NGC 2547 using the MPG/ESO 2.2-m telescope with Wide Field Imager, achieving better than 1 per cent photometric precision per data point over 14~<I~<18. Candidate cluster members were selected from a V versus V-I colour-magnitude diagram over 12.5<V<24 (covering masses from 0.9M_{sun}_ down to below the brown dwarf limit), finding 800 candidates, of which we expect ~330 to be real cluster members, taking into account contamination from the field (which is most severe at the extremes of our mass range). Searching for periodic variations in these gave 176 detections over the mass range 0.1~<M/M_{sun}_<0.9.
We present the results from a search for variable stars in the field of a young open cluster NGC 6755. Altogether seventy one variable stars have been discovered. Thirty one of them are eclipsing systems. This group contains ten EA, four EB and seventeen EW-type systems. Photometric variability of four late type stars is most probably caused by their chromospherical activity. Another seven detected variable stars have light curves typical for pulsating stars from the main instability strip. Four of them we tentatively classified as gamma Dor, one as delta Sct and two as Population II Cepheid variable stars, respectively. Star designated as V40 can be either another population II Cepheid or an ellipsoidal binary system. The remaining twenty eight variable stars found in the field of this open cluster are most probably highly obscured background red giants (OSARG, irregular). For all detected variable stars we provide their light curves, preliminary classification, discussion on the possible cluster membership, equatorial coordinates, finding charts and periods when possible.
From an ultra-low dispersion spectroscopic survey of the Cyg OB2 association several red and reddened stars are detected. Most of these stars appear to be reddened early-type stars belonging to the Cygnus OB2 association. The distance moduli V_0_-M_v_=11.2 and minimum reddening E(B-V)=1.2 suggests that some of the red stars in the magnitude range 15 to 17 are most likely reddened late B and early A main sequence stars of the Cyg OB2 association.
VIDEO DR5 - VISTA Deep Extragalactic Observations survey
Date:
25 May 2021 15:50:06
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VIDEO survey is a 30 sq. degree, Z,Y,J,H,K survey that is specifically designed to enable exploration of the main issues in observational cosmology. It allows galaxy and cluster/structure evolution to be traced as a function of both epoch and environment from the present day out to z=4 and AGN/QSO evolution up to and into the epoch of reionization at z > 6. The multi-band nature of the survey ensures many key science drivers can be tackled using the survey alone, without recourse to data from other wavebands.
VIDEO DR4 - VISTA Deep Extragalactic Observations survey
Short Name:
VIDEO DR4
Date:
04 Dec 2019 13:40:50
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VIDEO survey is a 30 sq. degree, Z,Y,J,H,K survey that is specifically designed to enable exploration of the main issues in observational cosmology. It allows galaxy and cluster/structure evolution to be traced as a function of both epoch and environment from the present day out to z=4 and AGN/QSO evolution up to and into the epoch of reionization at z > 6. The multi-band nature of the survey ensures many key science drivers can be tackled using the survey alone, without recourse to data from other wavebands.
VIDEO DR3 - VISTA Deep Extragalactic Observations survey
Short Name:
VIDEO DR3
Date:
04 Dec 2019 13:40:40
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VIDEO survey is a 30 sq. degree, Z,Y,J,H,K survey that is specifically designed to enable exploration of the main issues in observational cosmology. It allows galaxy and cluster/structure evolution to be traced as a function of both epoch and environment from the present day out to z=4 and AGN/QSO evolution up to and into the epoch of reionization at z > 6. The multi-band nature of the survey ensures many key science drivers can be tackled using the survey alone, without recourse to data from other wavebands.
VIDEO DR2 - VISTA Deep Extragalactic Observations survey
Short Name:
VIDEO DR2
Date:
04 Dec 2019 13:40:29
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VIDEO survey is a 30 sq. degree, Z,Y,J,H,K survey that is specifically designed to enable exploration of the main issues in observational cosmology. It allows galaxy and cluster/structure evolution to be traced as a function of both epoch and environment from the present day out to z=4 and AGN/QSO evolution up to and into the epoch of reionization at z > 6. The multi-band nature of the survey ensures many key science drivers can be tackled using the survey alone, without recourse to data from other wavebands.
VIDEO DR4 - VISTA Deep Extragalactic Observations survey
Date:
06 May 2015 00:45:51
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VIDEO survey is a 30 sq. degree, Z,Y,J,H,K survey that is specifically designed to enable exploration of the main issues in observational cosmology. It allows galaxy and cluster/structure evolution to be traced as a function of both epoch and environment from the present day out to z=4 and AGN/QSO evolution up to and into the epoch of reionization at z > 6. The multi-band nature of the survey ensures many key science drivers can be tackled using the survey alone, without recourse to data from other wavebands.
